MANHOLES, MUDHOLES, ETC.
||Sufficient sight and cleaning
holes shall be provided to permit of efficient inspecting
and cleaning. Such holes shall normally be elliptical
in form and not less than 3½ inches x 2½
* Note Standard sizes of mudholes and sightholes are
7x5; 5x3½; 3½x2½.
||At least one manhole or sight
hole shall be provided in the upper part of the cylindrical
shell or in the shell crown, or end plate and this shall
not be less than:-
|Boilers not exceeding 2 ft.
||9 x 7
|Boilers over 2 ft. 6 inches
diameter and not exceeding 3 ft.
||12 x 9
|Boilers over 3 ft. diameter
and not exceeding 3 ft. 6 inches
||14 x 10
|Boilers over 3 ft. 6 inches
diameter and not exceeding 4 ft.
||15 x 11
|Boilers over 4 ft.
||16 x 12
||Where the size or construction
of the boiler does not permit of entry for cleaning and
inspection sufficient cleaning holes shall be provided
in the shell for these purposes.
||Where cross tubes are fitted
in Vertical boilers one cleaning hole shall be provided
opposite at least one end of each tube. At the bottom
of the narrow water spaces at least three cleaning holes
shall be provided. The cleaning holes shall be so arranged
that the circumferential distance between them does not
exceed 3 ft. unless the foundation ring is sufficiently
accessible to permit of cleaning and inspection from the
inside of the boiler.
|NOTE.- Wherever practicable
the frames should be secured to the inside of the shells
so that the shorter axis is parallel to the longitudinal
centre line of the boiler.
||Cleaning holes or mud holes
in Loco Type boilers shall be provided at each bottom
corner of the outer firebox casing, above the fire hole
ring and on each side of saddle plate in line with bottom
||In the case of small boilers
or where the foregoing provisions are impracticable the
cleaning holes or mudholes shall be as nearly as possible
in the corner of the outer firebox casing and the holes
as large as circumstances permit.